The Scottish Crossbill - what we know and what we don't

The Scottish Crossbill Loxia scotica is Britain's only endemic bird. Given this status, together with its assumed small population size and its association with the few remaining scraps of native pinewood, the Scottish Crossbill has the highest of conservation designations. Its biology is poorly known, however, making it difficult to implement conservation measures. Here, we review some recent work which is investigating different aspects of the biology of crossbills in general and the Scottish Crossbill in particular. Museum, field and laboratory-based studies examining biometrics, vocalisations, feeding ecology, movements and genetics have now clarified some of the inter-relationships among the three crossbill species which are now recognised as breeding in Britain. Such efforts are also helping to identify the future research priorities required to maintain populations.